The present invention relates to an apparatus for accelerating a beam of charged particles, and more specifically to a disk-and-washer, coupled-cavity linear accelerator.
The disk and washer (DAW) linear accelerator (linac) structure, one type of coupled cavity linac, is widely recognized as one of the most efficient and stable accelerating structures for accelerating charged particles to velocities greater than half the speed of light. The DAW linac structure offers many desirable characteristics, such as superb accelerating structures for high-velocity charged particles, exceptional power efficiency, excellent field stability, and operational simplicity. One disadvantage of known DAW linac structures is that they are difficult and expensive to fabricate.
Heretofore, DAW linacs have been constructed by machining individual cells from solid billets of copper. This expensive, labor-intensive process proved quite impractical. Other manufacturing techniques have been investigated, such as hydrogen brazing. Although Los Alamos National Laboratory used hydrogen brazing to fabricate a DAW linac, brazing facilities which are currently available in private industry are unable to economically fabricate a DAW linac. For further information concerning the operation and structure of prior art linacs, reference may be made to "High Energy Accelerating Structures for High Gradient Proton Linac Applications" by Manca et al., IEEE Transactions on Nuclear Science, Vol. NS-24, No. 3, June 1977, pp. 1087-1090 and "PIGMI: A Pion Generator for Medical Irradiations" by Swenson, Los Alamos National Laboratory, Pub. LAL-81-6, Feb. 1981.